Closure element for internally pressurised bores in components

ABSTRACT

The closure element according to the invention is a tensioning pin ( 1 ) which can be tensioned and the head part of which forms a closure disc ( 2 ) that can be spread apart by the tensioning pin. Said closure disc is pressed, in the installed state, against the inner wall ( 6 ) of the bore to be closed. When a specific tensile stress is reached, the tensioning pin ( 1 ) is separated from the closure disc ( 2 ) at a predetermined breaking point ( 7 ) of the tensioning pin. The easy-to-handle tensioning pin facilitates the installation of the closure in the bore in the component. Since the closure disc ( 2 ) is pressed against an outer counterholder ( 9 ) during the installation process, it can be inserted into a continuously smooth bore. The limitation of the tensile stress effected by way of the predetermined breaking point also ensures that the bore is closed with a defined closing force.

The invention relates to a closure element for internally pressurised bores in components comprising a closure disc that can be inserted into the bore largely without any play and that can be spread apart by an axially applied tension and can thereby be pressed radially against the inner wall of the bore to be closed. The invention also relates to a method for installing the closure element in the bore of the component.

Closure elements of this type are used as mass-produced items in bores that have different diameters and internal pressures. A wide range of embodiments are produced depending on the size of the bore and the strength of the effective internal pressure. Some of these embodiments are disclosed in DE AS 1 120 415 and U.S. Pat. No. 6,708,978 B2. The closures described here are made as one-part closure discs. They are therefore easier to produce than multi-part closures, such as for example the closure described in WO 2009/000317 A1. Since however the closure discs have relatively small dimensions, they are often cumbersome to handle. In addition, the closure disc must be supported against an internal counter-surface of the bore during the installation process. As a result of this the bore must be precisely graduated in order to ensure that the closure disc has the exactly intended installation depth in the installed state.

The object underlying the invention is to avoid these disadvantages and to provide a closure element of the type specified at the start which can be installed easily in a continuously smooth bore and which closes the latter reliably with a defined closing force.

According to the invention this object is achieved in that the closure disc is the head part of a tensioning pin which can be tensioned and that this tensioning pin has a predetermined breaking point at which it can be separated from the closure disc upon reaching a specific tensile stress.

The tensioning pin integrated with the closure disc facilitates the installation of the closure in the bore of the component. By tensioning the pin support of the closure disc against an inner counter-surface of the component can be dispensed with. Since the tensile effect is limited by the predetermined breaking point, is it moreover ensured that in the installed state the bore is closed with a defined closing force.

The installation of the closure element in the bore of the component is implemented according to the invention such that the closure disc is first of all introduced with the tensioning pin and the latter is then withdrawn with a clamping jaw encompassing it, the tensioning pin pressing the closure disc against an outer counter-holder in the tensile direction until it is separated from the closure disc at the predetermined breaking point upon reaching a specific tensile stress.

The method according to the invention enables fast installation of the closure with an easy-to-handle device consisting essentially of the clamping jaw housing with the tensionable clamping jaws and the easily changeable mouth piece which acts as a counter-holder.

Preferred configurations of the closure according to the invention and of the method of installing the closure form the subject matter of the dependent claims.

In the following the invention is explained in greater detail using exemplary embodiments with reference to the schematically shown drawings. These show as follows:

FIG. 1 shows a first embodiment of the tensioning pin according to the invention with the corresponding installation device, shown in two phases of installation,

FIG. 2 shows different embodiments of the tensioning pin from FIG. 1,

FIG. 3 shows different embodiments of the lateral surface of the tensioning pin from FIG. 1,

FIG. 4 shows different embodiments of the tensioning pin from FIG. 1 with a face-side extension,

FIG. 5 shows different embodiments of the closure disc from FIG. 1,

FIG. 6 shows different multi-part embodiments of the closure disc from FIG. 1,

FIG. 7 shows different embodiments of the sealing surface of the closure disc from FIG. 1,

FIG. 8 shows different embodiments of the closure disc from FIG. 1 with machined sealing edges,

FIG. 9 shows different embodiments of the closure disc from FIG. 1 with different geometries of the sealing surface,

FIG. 10 shows different embodiments of the predetermined breaking point from FIG. 1,

FIG. 11 shows an embodiment of the predetermined breaking point for conical tensioning pins,

FIG. 12 shows a further embodiment of the predetermined breaking point,

FIG. 13 shows a first version of the installation device from FIG. 1 with clamping jaws gripping the tensioning pin securely,

FIG. 14 shows a second version of the installation device from FIG. 1 with a cutting or stamping tool for producing the predetermined breaking point,

FIG. 15 shows a third version of the installation device from FIG. 1 with a cutting or stamping tool integrated into the clamping jaws,

FIG. 16 shows three versions of the counter-holder from FIG. 1,

FIG. 17 shows a further embodiment of the counter-holder as a threaded part,

FIG. 18 shows two versions of the tensioning pin from FIG. 1 with carrying elements for a power spring,

FIG. 19 shows two further versions of the tensioning pin from FIG. 1 with threads for screwing on an additional component,

FIG. 20 shows a further version of the closure element made as a retaining element without a predetermined breaking point, and

FIG. 21 shows a further version of a closure element in a perspective view.

On the right of FIG. 1 the closure element according to the invention is shown in the starting phase and on the left in the final phase of the installation process. These closure elements are primarily used in automotive, pneumatic and hydraulic applications, such as for example as for the seals of bores in vehicle engines or of bores in hydraulic or pneumatic valves etc.

The closure element comprises a tensioning pin 1 with a head part in the form of a closure disc 2. This head part has an edge-side sealing surface 3 the outer diameter of which has dimensions such that it can be introduced into the bore 4 of a component 5 largely without any play. The easy-to-handle tensioning pin 1 facilitates the installation of the closure in the bore of the component.

As is evident from FIG. 1, the closure disc 2 is spread apart by the tensioned tensioning pin 1 and pressed with its sealing surface 3 radially against the inner wall 6 of the bore 4 until the tensioning pin 1 is separated from the closure disc 2 upon reaching a specific tensile stress at a predetermined breaking point 7 of the pin. The closure disc 2 is then anchored securely in the inner wall 6 of the bore 4 and closes it with a closing forced defined dependently upon the predetermined breaking stress.

The closure element according to the invention is installed with the aid of an installation device which is made up essentially of clamping jaws 10 with a clamping jaw housing 8, a withdrawal device (not detailed) and a counter-holder 9 placed on the component 5. The tensioning pin 1 is clamped securely with the clamping jaws 10 encompassing it. The easily changeable counter-holder 9 is constructed such that it projects more or less deeply into the bore 4 of the structure. In this way the installation depth of the closure can be specified from case to case. Since the tensioning pin 1 is tensioned, the counter-holder 9 is positioned behind the closure disc 2. It is therefore possible to provide the bore 4 with a continuously smooth inner surface.

Within the framework of the invention the counter-holder can also be in the form of a bush pressed into the bore or be formed by means of a narrowing of the bore.

FIG. 2 to FIG. 20 show further possible embodiments of the closure element according to the invention and of the corresponding installation device. In versions 1 a to 1 c according to FIG. 2 the tensioning pin is cylindrical or conical in form, and it can also be prismatic.

As is evident from FIG. 3, all or part of the tensioning pin can, moreover, have a roughened, serrated, fluted lateral surface 11 a to 11 d, or a lateral surface provided with a thread, to which the clamping jaws 10 can clamp securely with form or force closure. In the versions according to FIG. 13 the fluting or serrations are introduced by the clamping jaws 10 a and 10 b of the mouth piece formed in one or more parts.

In cases where high tensile forces are acting on the tensioning pin 1 or, for the purpose of providing a shorter structure, it is advantageous for reliably entraining the pin if it is provided with an extension 12 a to 12 d according to FIG. 4 on the end facing away from the closure disc.

In versions 2 a to 2 c according to FIG. 5 the closure disc 2 is slightly conical or spherical in form.

In versions 2 d to 2 h according to FIG. 6 the closure disc 2 is formed in a number of parts.

In the version according to FIG. 7 it has on the edge side a coated, roughened, fluted, serrated sealing surface 3 a to 3 f or a sealing surface provided with a thread or a sealing element, which guarantees secure anchoring of the closure disc. It is also advantageous in this context if at least the edge of the sealing surface lying on the outside is bevelled and optionally provided with an anti-sip machined surface according to versions 13 a, 13 b in FIG. 7. The sealing surface 3 itself is preferably cylindrical in form.

According to versions 14 a to 14 d in FIG. 9 it can, however, also be provided with a conical or concave or convex shape, for example for installation in bores that are not cylindrical in shape.

The predetermined breaking point 7 of the tensioning pin 1 is in the form of a groove or notch in versions 7 a to 7 c according to FIG. 10. With slightly conical tensioning pins it can be formed by its edge 7 d abutting against the closure disc 2 according to FIG. 11.

In the version according to FIG. 12 the tensioning pin 1 and the closure disc 2 are produced as individual parts securely connected to one another at the predetermined breaking point 7 e.

In the version according to FIG. 14 the predetermined breaking point 7 is introduced with a cutting or stamping tool 15 integrated in the clamping jaw housing 8 during the installation process.

In the version according to FIG. 15 the predetermined breaking point is also introduced during the installation process, in this case the cutting or stamping tool 15 being integrated onto the clamping jaws 10.

As shown in FIG. 16, the counter-holder can be graduated in accordance with version 9 a, the installation depth of the closure disc 2 being determined by the depth of the graduation. In version 9 b the counter-holder has a level supporting surface, and the closure disc 2 lies flush with the outer surface of the component. In version 9 c the counter-holder has approximately the diameter of the bore and the closure disc can be installed at any depth.

In version 9 d according to FIG. 17 a thread arranged in the component and into which the closure disc 2 is screwed serves as the counter-holder. This enables infinite setting of the insertion depth of the closure.

In the versions according to FIG. 13 to FIG. 15 the counter-holder 9 is integrated into the mouth piece of the installation device. The counter-holder 9 could also be formed as an individual part however.

The closure element can also be in the form of a retaining element. Possible versions are illustrated in FIG. 18 and FIG. 19.

In the versions according to FIG. 18 the closure disc 2 is equipped on the lower side with retaining means 16 a, 16 b for a power spring 17.

In the versions according to FIG. 19 it has on the lower side a thread 18 a, 18 b onto which a further component can be screwed.

In the version according to FIG. 20 the tensioning pin 1 is not pulled off by the sealing disc 2 during installation and any retaining functions can be fulfilled. For example, it could also be provided with a thread.

In the closure element according to FIG. 21 one or—as shown—a number of openings 21 are provided on the closure disc with a sealing surface 3 g. This type of closure element could be used in a bore in a valve or similar wherein the closure element allows a medium to pass through but, for example, retains a valve part that can be moved within the bore.

The closure element according to the invention can be produced either from metal, in particular aluminium or stainless steel, or plastic, machining processes, cold or hot forming processes and injection moulding processes being possible as methods of manufacture. 

1. A closure element for internally pressurised bores in components comprising a closure disc that can be inserted into the bore largely without any play and that can be spread apart by an axially applied tension and can thereby be pressed radially against the inner wall of the bore to be closed, characterised in that the closure disc (2) is in the form of a head part of a tensioning pin (1) which can be tensioned.
 2. The closure element according to claim 1, characterised in that the tensioning pin (1) has a predetermined breaking point (7) at which it can be separated from the closure disc (2) upon reaching a specific tensile stress.
 3. The closure element according to claim 1, characterised in that the tensioning pin (1) is provided with a peripheral surface (11 a to 11 d) that has been at least partially chemically or mechanically processed, for example roughened, serrated, fluted or provided with a thread.
 4. The closure element according to claim 1, characterised in that the tensioning pin (1) is provided on the end turned away from the closure disc (2) with an extension (12 a to 12 d) for withdrawing the pin.
 5. The closure element according to claim 1, characterised in that the closure disc (2 a to 2 c) is slightly conical or spherical in shape.
 6. The closure element according to claim 1, characterised in that the closure disc (2 d to 2 h) or the whole closure element is formed in a number of parts.
 7. The closure element according to claim 1, characterised in that the closure disc (2) has on the edge side a coated, roughened, fluted or serrated sealing surface (3 a to 3 f) or a sealing surface provided with a thread or a sealing element.
 8. The closure element according to claim 1, characterised in that at least the edge lying on the outside of the sealing surface (13 a and 13 b) is bevelled and is optionally provided with an anti-slip surface.
 9. The closure element according to claim 1, characterised in that the closure disc (2) is provided on the edge side with a conical, concave or convex sealing surface (14 a to 14 d).
 10. The closure element according to claim 1, characterised in that the predetermined breaking point (7 a to 7 c) is in the form of a groove or a notch.
 11. The closure element according to claim 1, characterised in that the tensioning pin (1) is slightly conical and the predetermined breaking point is formed by its face edge (7 a) abutting against the closure disc (2).
 12. The closure element according to claim 1, characterised in that the closure element is in the form of a retaining element, the closure disc (2) being provided on the lower side with retaining means (16 a, 16 b) for a power spring (17) projecting into the bore or with a thread (18 a, 18 b) projecting axially into the bore.
 13. The closure element according to claim 1, characterised in that the tensioning pin (1) and the closure disc (2) are formed as individual parts.
 14. The closure element according to claim 1, characterised in that the tensioning pin (1 a to 1 c) has a cylindrical or a slightly conical peripheral surface.
 15. A method for installing the closure element according to claim 1 in the component provided for this purpose, characterised in that the closure disc (2) with the tensioning pin (1) is introduced into the bore (4) of the component and then the tensioning pin (1) is withdrawn with a mouth piece (8) encompassing the latter, the tensioning pin pressing the closure disc (2) in the tensile direction against an outer counter-holder (9) until it is separated from the closure disc (2) upon reaching a specific tensile stress at the predetermined breaking point (7).
 16. The method according to claim 15, characterised in that the predetermined breaking point (7) is produced during the withdrawal process.
 17. The method according to claim 15, characterised in that the closure disc (2) is pressed against a counter-holder (9 a-9 c) placed on the component.
 18. The method according to claim 15, characterised in that the closure disc (2) is screwed into an inner thread (9 d) of the component serving as a counter-holder.
 19. The method according to claim 15, characterised in that the counter-holder is in the form of a bush pressed into the bore.
 20. The method according to claim 15, characterised in that the counter-holder is formed by means of a narrowing in the bore. 